Method for the preparation of a sustained-release dispenser of sex pheromone of pest insects

摘要

An improved method is proposed for the preparation of a sex pheromone dispenser used in the elimination of pest insects from the field by the disruption of mating of the insects by distributing sustained-release dispensers containing the sex pheromone compound of the insect over the field. According to the invention, pheromone dispensers made from a polyolefin-based resin and filled with the liquid pheromone are subjected, prior to distribution over the field at a relatively low temperature in early spring, to a pretreatment of keeping them at 35 DEG to 60 DEG C. until the dispenser walls of the polyolefin resin absorb 2 to 10% by weight of the pheromone. When the dispensers after the pre-treatment are distributed, a relatively high rate of pheromone release can be obtained at the low temperature as compared with untreated dispensers so that the rate of pheromone release can be relatively uniform over the whole period of the season in which the pheromone dispensers are kept over the field.